Safe Design and Maintenance of MEWPs

7/29/2019 Safe Design and Maintenance of MEWPs

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Safe Design and Maintenance ofMEWPsInternational Standards and Safety Devices and Inspections

Presenter

David Single

Product Parent for MEWPs and Telehandlers, J LG Australia

Australian Standards Committee Member for ME005-10 MEWP Standards and ME005-22Telehandler Standards.


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Content Types of Standards

Description ANSI

Description EN280

Explanation of CE Compliance

Description of ISO16368 and AS/NZ1418-10 2011

Structural Comparison

Stability Comparison

Safety Devices from MOM list.

Inspection and maintenance requirements of safetydevices, their location and function

Questions


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Types of Standards

Each country has their own OH&S Regulations. These are LAWS,and non -compliance brings prosecution. For AWPs / MEWPs there are internationally acceptable

Construction standards, developed by Industry Associations andRegulators, and use the State of Knowledge and Best Practiceprinciples, as well as well proven in use and proven reliable

design. Concensus Standards are Guidance documents, NOTLAWS. The Standards are guidance documents and are used to determine

if the AWP/MEWP meets the structural, stability and safetyrequirements of the OH&S regulations in each country. DifferentStandards can use different methods to get to the same safetyoutcome.

Based on this you could use a proven international standard, eitherANSI A92 series of 5 individual standards (USA) , EN280 Standard(European Norms), ISO16368 (International) or AustralianStandards new draft of AS/NZ 1418-10 2011, to comply with thecountries OH&S Laws.


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ANSI TypesANSI has five (5) separate standards.The Scaffold Industry Association (SIA) serves as a secretariat for the ASC A92 Main Committee. ASC A92Standards are applicable to U.S. operations. They are used by manufacturers, dealers, owners, users andoperators of AWP equipment. The purpose of the standards is the proper and safe use of machines andthe prevention of accidents and injuries. These standards also establish cr iteria for the manufacturersas well as aid the manufacturers, dealers, owners, users and operators of AWP equipment to

understand their various responsibilities. This document references the fol lowing A92 Standards:


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Description ANSIRoles of ANSI and OSHA

ANSI promotes safety in the industry by developing recommendations in the form of standards and guidelines. While

ANSI standards are considered recommended guidelines, they are not laws or regulations. Complying with ANSIstandards is voluntary.

OSHA is an agency of the U.S. government that issues and enforces regulations for employers to ensure workplacesafety and health. Though the regulations are often referred to as standards, they are in fact federal laws andtherefore compliance is mandatory.

Reasons for Complying

ANSI standards and OSHA regulations are often confused because they generally address the same issues. Infact, many OSHA regulations were written based on ANSI standards. Also, OSHA often adopts ANSI standardsvia incorporation by reference. When standards are adopted or incorporated, they become part of the OSHAregulation and are no longer voluntary.

To the extent that the current ANSI standards are not incorporated into OSHA regulations, the ANSI standards arevoluntary. However, ANSI standards provide guidance as to what may be considered the standard of care. If youcomply with ANSI standards, you may have an argument for a defense against claims under OSHAs generalduty clause, which requires employers to keep the workplace free from recognized hazards.

OSHA has written many rules in the Code of Federal Regulations (CFR), but in some cases has adopted consensusstandards to be used as minimum guidelines by their reference in the Code of Federal Regulations. In 1974, theyadopted many of the ANSI and National Fire Protection Association (NFPA) standards in order to promote safetyrules. In this particular time frame, there was only one aerial lift standard, A92.2-1969 for vehicle-mountedelevating and rotating work platforms.

ANSI has since created other standards for other types of aerial lifts and OSHA recognizes these consensus standards.

OSHA also has referenced these consensus standards through interpretive letters regarding compliance. All contributing organizations fully support the ANSI/SIA A92 Standards as the recognized standards for AWPequipment. The associations and their members are actively involved on the ASC A92 Main and Subcommittees.

Extract from 02-11-AWP-SBP002 Statement of Best Practice for PFP Feb 2011. Keywords: Voluntary, Mandatory, Standard or care, Concensus Standards.


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EN280

Types


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Description EN280 EN280 is what CE refers to as a "harmonized" standard, which is equivalent to what you refer to as a "consensus"

standard. The OH&S regulations are defined in the Machinery Directive, and compliance to the MachineryDirective is mandatory fo r machines sold in the CE market. EN280 provides specific guidance on complianceto the Machinery Directive for AWPs. It represents what CE considers to be "best practice," and full compliance to

EN280 gives a presumption of conformance to the Machinery Directive within the CE market. Exceptions toEN280 must be reviewed and approved by the notified body.

This European Standard has been prepared under a mandate given to CEN by the European Commission and theEuropean Free Trade Association, and suppor ts essential requirements o f EU Directive(s).

According to the CEN/CENELEC Internal Regulations, the national standards organisations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden,Switzerland and the United Kingdom.

This European Standard specifies technical safety requirements and measures for all t ypes and sizes ofMobile Elevating Work Platform (MEWP) intended to move persons to working positions where they arecarrying out work from the work platform (WP) with the intention that persons are getting on and off the workplatform only at access positions at ground level or on the chassis.

Furthermore it is assumed that persons on the work platform in case of power supply failure are NOTincapacitated and can assist in the operation of the overriding emergency device.

- As far as possible this European Standard sets out only the requirements that materials and equipment have tomeet in the interest of safety, and it i s assumed that persons operating MEWPs are adequately trained.

- Where for clarity an example of a safety measure is given in the text, this shall not be considered as the onlypossible solution.Any o ther solut ion leading to the same risk reduction is permiss ib le if an equivalent levelof safety is achieved.

The use of EN 280, without the EU Machinery Directive behind it, could block a lot of machines from beingimported, as very few machines, if even any, will meet all requirements in EN 280.

Key words: EU Directives, European Standard, NOT incapacitated, Adequately trained operator, other safety solution.


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Explanation of CE Compliance CE is not a standard. It is CE Compliance, a document identifying compliance to the European Machinery

Directive, using EN280 Standard as a guidance document, and employing an ECNotifying Body (such as SGS, RINA, PAC, TUV etc ) proving compliance to and/oraccounting for exceptions to the EN280 Standard.

Compliance Exceptions can be details such as platform dimensions, enhancedstability and enhanced overload in place of LSS.

The EC Notifying body could also be referred to as an Independent 3rd PartyCompliance Verifier.

As the CE Compliance is compliance to the EU Machinery Directives (theEuropean OH&S Regulations) and this compliance is MANDATORY, so any futurechanges in the EU Machinery Directives would require the accepting entity in anothercountry to comply with the new EU Machinery Directives.

An example of this is: If the EU Machinery Directive directs that platforms are paintedPINK, they must be painted PINK. If you paint them White, you are in breach of thecompliance certificate. If you remove devices or change the machine features foranother market, it NO LONGER complies with the Machinery Directive. That means

you have a NON Compliant MEWP. If you change the controls on a boom to allowdrive/boom functions simultaneously, then the unit is no longer CE compliant.

CE Compliance is effectively only valid in the European countries. The EC notifyingbody must renew the CE compliance certificate every 5 years. Acceptance of aEuropean countries OH&S Regulations are part of the requirement.


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Description of ISO16368 andAS/NZ1418-10 2011

The ISO Standard ISO16368 is a work item of the International Standards Organisation. It hasdifferences to the EN280 Standard and was used as a template for the new Australian Standard,as Standards Australia is an ISO member. You cannot change the wording of an ISO standardand must take up the contents in its entirety. NO recognized manufacturers build MEWPs orAWPs to the ISO16368 Standard. There are also additional ISO Standards for truck mountedplatforms.ISO16368 should NOT be considered as a working standard for the ASEAN market, as nomanufacturer builds MEWPs to this standard.

The AS/NZ1418-10 2011 standard is a product of a ISO 16368 template, with all the current stateof knowledge, AS1418-1, AS1418-10 2004 ANSI, CSA and EN280 sections mixed in the draft. Itcovers all ranges of MEWPs, with additional sections 5, 6 & 7 to cover the VARIATIONS from themain body of the standard for particular MEWP types. Work started in 2004 on this draft.

Note: AS/NZ1418-10 2011 is also a combined New Zealand standard, and New Zealandwill need to apply this standard to all new MEWPs imported into and MEWPs manufactured inNew Zealand for the Australian & New Zealand Market. Machines built for export from Australiaand NZ can be the Standard of the importing market, EN280, ANSI etc.

The AS1418 series of Standards, are part of the Crane Standards in Australia.

The AS/NZ Standard should not be considered as a Standard of choice for ASEAN region,as it contains sections relevant to Australian applications and ties into too many AustralianStandards that are not valid in the ASEAN market. There is no impediment to importing anAS/NZ1418-10 2011 Compliant machine into the ASEAN market. Compliance Verificationdocuments need to be presented and checked..


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AS/NZ1418-10 2011 Extras


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Structural ComparisonANSI EN280

ANSI structural factor of

safety is 2.75

EN280 does not specify a structural factor of safety.

General steel guidelines specify a minimum of1.67

EN280 designed units are usually a lighter structure, most notable on theslender boom dimensions.

Where other devices such as truck cranes are used as MEWPs, the Craneshigher factor of safety allows removal of the LSS system. The EN280design takes into account all loads, including wind loads. To protect thestructure from structural overload, LSS is a critical part of the assembly.

MEWPs shall be provided with control devices thatreduce the risk ofoverturning and the risk of exceeding permissible stresses.

NOTE: It should be noted that load or moment controls are not able to

protect against an overload that gross ly exceeds the rated load.

Cylinder Burst pressures are

rated as four (4 ) times thesystem pressure.

Cylinder burst pressure is rated at a ratio of rod/piston diameter. The hose

and fittings burst pressure is rated at three (3) times the maximum reliefpressure.


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Stability ComparisonANSI

AWPs rated for level ground and tested on 5

degree incline

EN280

Rated for use on level ground, but can be used

for chassis inclination on the manufacturers plate.Tested at the incline on the Compliance plate,plus additional degree.

Static load test on slope

The aerial platform shall be tested on a slope 5degrees greater than the slope for which it is

rated by the manufacturer. The test shall beconducted:

(1) While sustaining static vertical load equal to1.33 times the rated work load of the platformapplied the platform floor surface at a location 12inches (0.30m) inboard from the railing or floortransition, or on the platform centreline, whichever

places the center of gravity of the load closest tothe guardrail.

Static tests

The MEWP shall be set up on the maximumallowable chassis inclination defined by the

responsible entity plus 0,5. Stabilizers, ifprovided, shall be used as specified by theresponsible entity. If the MEWP is supported inthe working position by pneumatic tyres and is notprotected by a low-tyre-pressure operator warningsystem, the MEWP shall be set up with theinclination taking into account a deflated tyre. Test

loads shall be applied to represent all the leastfavourable load and force combinations


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Stability Test SampleSample 60ft boom at ANSI forward stability test.

AWP set up on 5 degree incline, 133% load and manualforce load applied to handrail of 150lb or 15% of capacity,or 50lb per person, whichever is greatest.

Sample 60ft boom at EN280 forward stability test.

MEWP set up on 3 degree +0.5 degree. Apply test loadplus 10%, apply manual force load of 400N plus 10%,apply wind load +10%.

Test slope is 5 degree = ANSIRated capacity 500lb/230kg x 1.33 =306kg

Must remain stable with the boom extended

horizontal with 306kg @ 5 degree slope.

THIS DOES NOT CONSTITUTE A STABILITYTEST, SAMPLE ONLY

3.5 degree Chassis inc lination = EN280 with LSS

Rated capacity 500lb/230kg x =230kg

Manual force 400N x 1.1 =45kg

Wind load @ horizontal boom angle x 1.1 =5kg x 1.1 =5.5kg, Must remain stable and not overturn with the boom

extended horizontal with 280.5kg @ 3.5 degreeOr

Wind load @ 80 degree boom angle x 1.1 =55kg x 1.1 =60.5kg .Must remain stable and not overturn with the

boom fully elevated with 330kg @ 3.5 degree


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Safety devices from the MOM List

Proposed List of mandatory safety devices for mobile elevated work platform (MEWP)

1)Level indicatorLevel indicator to indicate whether the inclination of the MEWP chassis is within the limits permitted by the manufacturer.

2)Load sensing systemLoad sensing system to alarm and stop the work platform when certain rated load situations have been exceeded.

Note:a) If the load sensing system was triggered during normal movement of the work platform, the possibility of normal movement mayremain.b) For MEWPs, where the vertical projection of the centre of gravity of the load is always inside the tipping lines, the load-sensing systemneed not be activated until the work platform is elevated more than 1 m or 10 % of lift height, whichever is the greater, above the lowestposition. If an overload condition is sensed at or above this height, further elevation shall be prevented.

3)Position controlMechanical stops or control systems to limit the MEWP to its working envelope.

4)Moment sensing systemMoment sensing system to provide visual warning when overturning moment is reached and prevents further movements, except thosethat reduce the overturning moment

5)Movement Controlsa) MEWPS shall be provided with controls such that all movements of the MEWPS can only take places whilst the controls are beingactivated. The controls, when released shall automatically return to the neutral position. The travel controls in the cabs of vehiclemounted MEWPs do not need to be of this type.b) All controls, especially foot operated controls, shall be constructed to prevent inadvertent operation.c) The control devices shall be situated on the work platform. This does not preclude the provision of duplicate controls operated from the

base or ground level. Duplicate controls shall be protected against unauthorized operation.6)Emergency stop butt on

MEWPS shall be provided with emergency stop button. All machine functions are disabled when the button is activated.


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Safety devices from the MOM List1. Level Indicator

ANSI EN280

1. Spirit level on Vertical lift.

2. Level sensor alarms on boom typeMEWPs when elevated andchassis reaches themanufacturers level sensorsetting on slope.

1. Spirit level on Vertical lift.

2. Level sensor cuts lift up onlyonscissorlift (Group A -type 3) whenelevated and chassis exceedsmanufacturers rated slope. Elevateddrive speed still available to

continue driving on the slope.

3. Level sensor alarms on boom typeMEWPs when chassis reaches theextreme limits of inclination.


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Safety devices from the MOM List2. Load Sensing system

ANSI LSS not installed. EN280 LSS installed to protect from exceedingstructural stresses and overturning.

1. Structural factor of safety2.75

2. Cylinder burst pressure ratio4:1

Exceeding structural stresses andoverturning covered by ANSIstructural factor of safety andANSI stability test.

1. Structural factor of safety not specified.2. Cylinder burst pressure ratio based oncylinder piston/rod dimensions, and hoses andfitting at burst pressure ratio of 3:1

3. LSS in platform cuts platform functions ifload exceeds 120%.

Can only be overridden at ground controls, orremove overload and reset controls.

4. Enhanced stability based on smaller platformdimensions and enhanced overload can beused, Needs an EC Notifying body verificationor full EN280 compliance.As/NZ1418-10 2011 Australian Spec, override at platform emergency pump controls.

S f t d i f th MOM Li t


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Safety devices from the MOM List3. Position Control

ANSI Envelope control system EN280 Envelope control system.

1. Large multi extension booms thatreach taller than the ability toreach horizontal, are envelope

controlled AWPs. These can bestraight telescopic, or telescopicknuckle booms.

2. The safety devices for thesefunctions are the same as in

EN280.3. Devices include redundant length

sensors and redundant anglesensor and redundant limitswitches

1. Where non-mechanical limiting devicesare used, permissible positions of theextending structure shall be limited by a

device which measures positions of theextending structure, and operates throughthe control systems to limit movements tothe working envelope. This device shall bebacked up by a safety device.

.


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Safety devices from the MOM List4. Moment Sensing System

ANSI EN280 moment sensing system installed to protect fromexceeding structural stresses and overturning.

1. Moment sensing, a systemthat prevents the boom fromexceeding positive loads that

create forward instability andoverturning, and negativeloads to prevent rearwardinstability and overturning.

2. The moment system can bea load pin and angle positionsensor, or stabiliser contact

pressure sensor to indicatethat the AWP is close to thedesign limits before instabilityoccurs. These devices(where installed), are thesame as EN280 devices.

1. The moment sensing system is a safety device andshall operate in the following way:

- When the permissible overturning moment is reacheda visual warning shall be given

and further movements shall be prevented except thosewhich reduce the overturning moment.

-The control system for the moment sensing systemshall comply with the safety system


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Safety devices from the MOM List

ANSI EN280 Controller direction and override fromground controls

1. J oysticks move in the direction of travel, and

are protected from inadvertent operation byenable /deadman footswitch or separatehold to run enable switch on the platformcontrols.

2 ANSI AWPs allow travelling controls, (drive) andboom functions to operate simultaneously.This allows swing, lift up, jib and platform

level functions to aid the ground surfacevisibility for the operator.

3. Ground duplicate controls (not travellingcontrols) enable the person on the groundto retrieve the operator in the elevatedplatform.

1. On MEWPs of types 2 and 3 it shall not be possible forthe travelling controls to be operated simultaneously withany other controls.This does not apply to rail mountedMEWPs. This shall be achieved by a safety device.

2. The control devices shall be situated on the workplatform. This does not preclude the provision of

duplicate controls operated from the base or ground level.Duplicate controls shall be protected against

unauthorised operation and may be used to serve as theemergency device

If movement can be controlled from different controlpositions, the controls shall be interlocked at the duplicate

control position in such a way that control is only possiblefrom one pre-selected control position. This shall be

achieved by a safety device

5. Movement Controlsa) MEWPS shall be provided with controls such that all movements of the MEWPS can only take places whilst thecontrols are being activated. The controls, when released shall automatically return to the neutral position. The travel

controls in the cabs of vehicle mounted MEWPs do not need to be of this type.b) All controls, especially foot operated controls, shall be constructed to prevent inadvertent operation.c) The control devices shall be situated on the work platform. This does not preclude the provision of duplicatecontrols operated from the base or ground level. Duplicate controls shall be protected against unauthorized operation.


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Safety devices from the MOM List6. Emergency Stop Button

ANSI EN280 Emergency stop switch.

1. Emergency stop device. Theaerial platform shall be equippedwith readily identifiable

emergency stop devices, locatedat the upper control and lowercontrol stations, which deactivateall powered functions.

2. The ground controls override the

platform emergency stop toenable the possible need toretrieve an operator.

1. MEWPs shall be provided withemergency stop controls in accordancewith EN 418 at each control position.

Emergency stop controls are not requiredon MEWPs with full-flow control valves withcontrol handles connected mechanically tothe control valve spools (manual override).

MEWPS shall be provided with emergency stop button. All machine functions

are disabled when the button is activated.


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Safety device location.


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Safety Devices Function and Inspection.Sample for Boom type MEWPs


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Provision for emergency retrieval Retrieval of platform in the event of

loss of normal power

Ground controls Lower controls return to off and correctly labelled Lower controls isolate upper controls Emergency controls Duplication of controls Emergency deadman functions correctly Removeable key switch or other lockable ground controls Mushroom emergency stop switch coloured RED Motion alarm sounding when lifting or travelling Strobe or Flashing light operating when travelling

Level Sensor Inclination alarm On a self-propelled MEWP, an acoustic signalaudible alarm at the work platform shall operatewhen the extreme limit of inclination has been reached


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Tyres: Tyre pressure labels, where tyres are pneumatic. Puncture proof tyres.Urethane ( Foam Filled indicated usually by a Coach bolt visible opposite the

valve stem to release trapped air during curing) Solid cushion tyres.

Out-of-service brake The self-propelled elevating work platform shall beequipped with a brake capable of holding it in the out-of-service mode

In-service brakeThe self-propelled elevating work platform shall beequipped with a brake capable of holding it on a slope that can benegotiated by the platform when loaded

Swing drive brakeThe self-propelled MEWPshall be equipped with a brake capable of holdingthe rotating structure it on a the maximum slope,at the limit of inclination.


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Platform Platform to be in good condition withoutevidence of excessive damage, corrosion debris etc. An open platform shall incorporate the following: (a) A non-skid floor.

(b) Guard-railing or other structure around its upper periphery notless than 1 m above the platform floor. (c) A mid-rail. (d) Kick-plates at sides and ends not less than 100 mm high. The

kick-plate may form partn of the means of ingress and egress. (e) Drain holes, where the floor has no other openings.

GateWhere provided, hinged access doors should open inwards. Hinged

access doors shall automatically and positively return to the closedposition and be self-locking. Drop bars fulfil this purpose.


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Fall Arrest Anchor Points

Boom-type MEWPs shall have suitableanchorages for the attachment of safetyharnesses for each occupant. Each anchorageshall be designed to withstand the forces specified.

Platform Controls

Upper controls correctly labelled. Upper controls return to off and neutral position. Emergency controls Emergency dead-man/Enable trigger switchfunctions correctly Mushroom emergency stop switch, coloured RED.

Platform controls mounted correctly,lever below guard rail. Foot Switch Assembly Platform alarms and indicator lights.


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Hydraulics

All hydraulic hoses in serviceable condition

and routed correctly

No evidence of oil leakage from reservoir

No evidence of oil leakage from hoses

No evidence of oil leakage from hydraulic valves

No evidence of oil leakage from steer cylinder(s)

No evidence of oil leakage from lift cylinder(s)

No evidence of oil leakage from telescope cylinder

No evidence of oil leakage from platform level cylinder(s) No evidence of oil leakage from jib boom cylinder

No evidence of oil leakage from Drive motors

No evidence of oil leakage from Swing motor


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Electrical

Electrical looms adequately installed and protected Electrical switches secured and operational Work lights function correctly (if fitted) Rotating beacons operate correctly (if fitted)

Limits switches secured and operating. Elevated boom travel limit switch Telescopic boom limit switch Envelope control limit switch Drive orientation limit switches

Envelope control system (where fitted) Moment control system (where fitted ) Axle limit switches

Documents

Safe Design and Maintenance of MEWPs